Global Patent Index - EP 0512625 A3

EP 0512625 A3 19921202 - OPTICAL SCANNING DEVICE

Title (en)

OPTICAL SCANNING DEVICE

Publication

EP 0512625 A3 19921202 (EN)

Application

EP 92201218 A 19920504

Priority

EP 91201139 A 19910510

Abstract (en)

[origin: EP0512625A2] A device is described for scanning an information plane having tracks in which a track to be scanned is tracked by means of the three-beam method. Each one of the three beams is push-pull detected by three split detection systems (10, 11, 12). A position signal Ep which is a measure of the position of an adjustable element (9) in the device determining the transversal position of the spots with respect to the tracks is derived from the detector signals by means of a special electronic circuit (24-26, 30-32). A control circuit 33 can correct the position of the element by means of the position signal. A normalizing signal with which the position signal Ep is made independent of the intensity of the beams can also be derived from the same detector signals. <IMAGE>

IPC 1-7

G11B 7/09

IPC 8 full level

G11B 7/085 (2006.01); G11B 7/09 (2006.01); G11B 7/095 (2006.01)

CPC (source: EP US)

G11B 7/08517 (2013.01 - EP US); G11B 7/0903 (2013.01 - EP US); G11B 7/094 (2013.01 - EP US); G11B 7/0943 (2013.01 - EP US)

Citation (search report)

  • [AP] WO 9015408 A1 19901213 - SONY CORP [JP]
  • [A] EP 0409469 A2 19910123 - SONY CORP [JP]
  • [AD] PATENT ABSTRACTS OF JAPAN vol. 13, no. 116 (P-845)22 March 1989 & JP-A-63 291 224 ( BROTHER ) 29 November 1988
  • [A] PATENT ABSTRACTS OF JAPAN vol. 12, no. 429 (P-785)14 November 1988 & JP-A-63 160 021 ( NIPPON COLUMBIA ) 2 July 1988

Designated contracting state (EPC)

AT BE DE FR GB

DOCDB simple family (publication)

EP 0512625 A2 19921111; EP 0512625 A3 19921202; EP 0512625 B1 19970903; AT E157796 T1 19970915; CN 1032276 C 19960710; CN 1066733 A 19921202; DE 69221931 D1 19971009; DE 69221931 T2 19980305; JP 3720851 B2 20051130; JP H05128548 A 19930525; TW 226046 B 19940701; US 5173598 A 19921222

DOCDB simple family (application)

EP 92201218 A 19920504; AT 92201218 T 19920504; CN 92103463 A 19920507; DE 69221931 T 19920504; JP 11754592 A 19920511; TW 81101051 A 19920214; US 73392691 A 19910722